Brake mechanism for railway cars



Aug. 13, 1929. r H, z c 1,724,512

BRAKE MECHANISM FOR RAILWAY- CARS Filed Oct. 5. 1927 s Sheets-Sheet 1Fig.3.

3, 1929. F. H. PIETZSCH 1,724,512

BRAKE MECHANISM FOR RAILWAY CARS Filed Oct. 3, 1927 3 Shgets-Sheet 2 7 gg 2 A Inventor 'F. Pietzsch 1929- F. H. PIETZSCH 1,724,512

BRAKE MECHANISM FOR RAILWAY CARS Filed 001;. 3, 1927 I s Sheets-Sheet sZ FiglO,

' Inventor F. H, Pietzsch,

By lfim Att'y.

- an enlarged view on the line 44 of Figure- Patented Aug. 13, 1929UNITED STATES PATENT OFFICE.

FRANK H. PIE'IZSCH, OF ST. LOUIS, MISSOURI, ASSIGNOR '10 RAILWAY DEVICESCOM- PANY-;OF ST. LOUIS, MISSOURI, A CORPORATION OF MISSOURI.

BRAKE MECHANISM FOR RAILWAY CARS.

Application filed October 3, 1927. Serial No. 223,827.

' My invention relates to a brake mechanism for railway cars and isparticularly applicable to the type of mechanism known as hand brakes.The object of my invention is to provide an improved form of mechanismin which the brake mechanism w1ll be moved rapidly during the first partof the operation to take up the slack, and slowly and withcorrespondingly increased power during the latter part of the operationwhen the brake shoes are applied to the wheels.

In the accompanylng drawings, which 11- lustrate two forms of brakemechanism made in accordance with my invention, Figure 1 is a front viewof one form; Figure 2 s a side elevation; Figure 3 is an enlarged viewon the line 33 of Figure 1; Figure 4 1s 1; Figure 5 is a top plan viewof another form; Figure 6 is a rear elevation of the form shown inFigure 5; Figure 7 is a horizontal section through the guide shoe;F1gure 8 is a side elevation of the guide shoe; Figure 9 is asemi-diagrammatic view showing the relation of my device to the brakestaff and brake cylinder; and Figure 10 1s a diagram illustrating themovement of the parts. 0

Referring first to Figures 1 to 4, whlch illustrate a brake mechanism ofthe type having a vertically disposed hand wheel, 11 indicates the endof a car provided with the usual hand wheel 12 having ratchet mechanism13 and actuating a short horizontal shaft 14 on which a chain 15 iswound to set the brake. Secured to the end of the car is a bracket 16preferably provided with a housing 17 for the shaft and carrying a guideshoe 18 and a pivot pin 19. Mounted on the latter is the inner end of anarm 20, on the outer end of which is mounted at a point 21 intermediateof its length a lever 22 connected at one end to the chain 15 andcarrying on the other end guide wheels 23 cooperating with the track ofthe guide shoe 18. This track comprises a lower part 24 lyingapproximately in an are having its center at the pivot point 19 of thearm 20, and an upper part 25 lying in a line approximately radial tosaid pivot point. Connected to the pivot point 21 by meansof a V yoke 26is the upper end of a rod 27 the lower end of which is connected by abrake jaw 28 to a bell crank lever 29 carried on the 33 and actuates achain 34'corres onding to the chain 15hereinbefore descri ed. This chamis connected preferably by means of a rod 35 with the power changing orbooster mechanism which, in this form, is situated under the car insteadof against its end. The inner end of the rod 35 is pivoted at 36 to thelever 22 mounted on the arm 20 which, in this form of the device, ismounted on a plate 37 and is provided with an extension to which isattached a spring 38. Carried by a sill 39 is a bracket 40 supportingthe guide shoe 18 to which is attached one end of the plate 37, theother being carried by a bracket 41 to which the spring 38 is alsosecured. A guard 42 secured to the plate 37 holds the arm 20 against thelower face of the plate and also forms. a stop to limit the movement ofthe arm in either direction. Secured to the yoke 26 is a chain 43attached to the pushrod 44 of the brake cylinder 45 which actuates thebrake beam 46 to operate the brake rods 47.

The operation of my device will be clear from the diagram Figure 10. Theinitial positions of the pivot points 36 and 21 and the axis of theroller 23 are indicated by the letter S. As power is applied to thepivot 36 through the hand wheel and connections this point travels alongthe line A causing the pivot 21, which communicates power to the brakemechanism, to travel along the arc B having the point 19 as its center.The pull on the opposite end of the lever 22 causes the roller 23 tobear against tracks 24, 25 so that the axis of the roller travels alongthe line 0 parallel to said tracks. During the first part of themovement while the roller is in contact with the part 24 of the trackthe arm 20 and lever 22 move substantially as a unitary part, whileafter the roller comes in contact with the part 25 of the track thelever 22 swings on the pivot 21 the two parts now acting as a togglethus the .position of themoving points when the roller reaches the upperend of the track 24; letter Y their position when itreaches its extremeposition on the track 25; and the letter Z the extreme movement of thepoint-s 36 and 21 which causes the roller to recede on the track 25. Itwill be seen that the vertical distance between the points S and X onthe line A, which represents the movement of the actuating devices, ismuch less than the corresponding vertical distance S-X on the line B,which represents the movement applied to the braking mechanism and whichis suflicient to take up the normal slack in said mechanism, while thevertical distance X-Z on said line A is greater than the correspondingvertical distance on the line B indicating the increased power appliedto the brake mechanism. This latter movement is sufficient not only toapply the brake with the normal amount of slack in the connection butalso to take up any additional slack which may develop from wear of theparts.

Having fully described my invention, what I claim as new and desire tosecure by Letters Patent of the United States is:

1."In a device ofthe class described, the combination with manuallyoperated power applying means, of brake mechanism, and a boosterinterposed therebetween, said booster comprising an arm, a lever pivotedthereto, and guide mechanism causing said arm to move approximately inunison with the lever during the first part of the braking operation andto act as a toggle during the latter partof said operation.

2. In a device of the class described, the combination with manually 0erated power applying means, of brake mec anism, and a boosterinterposed therebetween, said booster comprising an arm having a. fixedpivot, a lever pivoted thereto, and a guide consisting of twointersecting tracks cooperating with said lever to control the relativemovement of said arm and lever during the braking operation.

3. A booster for railway brakes comprising an arm having a fixed pivot,a lever pivoted to said arm, power applying connection attached to oneend ofsaid lever, a guide shoe cooperating with the other end of saidlever, and brake applying connections operated from the booster.

4. A booster for railway brakes comprising an arm having a fixed pivot,a lever pivoted to said arm, a power applying connection extending toone end of said lever, a guide shoe cooperating with the other end ofsaid lever and having two intersecting tracks, and brake applyingconnections operated from the booster.

5. A booster for railway brakes compriss ing a pivoted arm, a leverpivoted to said arm, power applying connection attached to one end ofsaid lever, a guide shoe cooperating with the other end of said leverand having two intersecting tracks, and a brake applying connectionextending from the point of connection between said arm and lever.

6. In a device of the class described, the combination with manuallyoperated power applying means, of an arm having a fixed pivot, a leverpivoted to said arm, a guide cooperating with the lever to controltherelative movement of the arm and lever, said guide comprising a portionlying approximately in an are having said fixed pivot as a center and asecond portion diverging from said are, a connection extending to saidpower applying means, and a second connection extending to a brake.

7. In a device of the class described, the combination with manuallyoperated power applying means, of an arm having a fixed pivot, a leverpivoted to said arm at a point intermediate of its length, a guidecooperating with one end of said lever, said guide comprising a portionlying approximately in an are having said fixed pivot as a center and asecond portion diverging from said are, a connection extending from saidpower applying means to the end of the lever op posite said guide, and asecond connection extending from the pivot point of the lever to abrake.

In testimony whereof, I hereunto atfix my signature, this 30th day ofSeptember, 1927.

FRANK H. PIETZSCH.

